The primary goal of this proposal is to organize a laboratory that can study complex neurobiological problems at levels ranging from the molecular to the behavioral. In addition, this Career Development Award would free up time to learn about self-administration and electrophysiology so that these techniques can ultimately be performed in this laboratory rather than in collaboration. Another important goal of this application is to allow for time to improve conditional knock-out studies, so that ultimately gene expression can be controlled both temporally and spatially in brain areas of transgenic mice. The studies proposed therefore involve traditional pharmacological, biochemical, and behavioral experiments, as well as use of transgenic and knock-out technology. The career development plan involves attendance at physiology seminars and hands on work with faculty members whose expertise is in mammalian electrophysiology. In addition, I will do experiments with behavioral neuroscientists studying self-administration and other mouse behaviors. Hands on work will be supplemented with seminars in this area and a class in statistical analysis of behavioral data. Finally, this proposal will allow time for attendance at meetings on the latest conditional technologies in the mouse, as well as the time to perform experiments in the laboratory to optimize this technology. The Specific Aims of this project are to use these new techniques to determine the molecular events underlying nicotine addiction, to determine how nicotine affects responses to other drugs of abuse, to examine the role of the high affinity receptor for nicotine in learning and memory, and to develop new tools to examine the role of nicotinic receptors in specific brain areas and at specific times in development. These Aims will be achieved using wild-type mice, traditional knock-out mice that lack expression of the beta2 subunit of the neuronal nicotinic receptor throughout development in all tissues, and mice that conditionally express this subunit only in particular brain areas under the control of the tetracycline-regulated promoter. Together these different approaches will build a bridge between molecular biological data on nicotinic receptor subtypes and the large body of behavioral pharmacological literature on the actions of nicotine in vivo.